Distinguishing Between Alzheimer's Disease, Lewy Body Dementia, and Parkinson's Disease

The study will use structural and functional MRIs, daTscans, fluorodeoxyglucose (FDG) PET scans, Amyvid PET scans, polysomnographs, neuropsychological testing, cerebrospinal fluid in willing participants to distinguish between a diagnosis of Alzheimer's disease, Lewy Body dementia, and Parkinson's Disease. All subjects will have a clinical evaluation, physical examination including vital signs and orthostatic blood pressures and pulses, neurological examination including UPDRS evaluation, genetic blood sample collection, neuropsychological testing, polysomnogram, and neuroimaging. The study partner will also be interviewed for completion of all of the behavioral and functional measures.

• DaTscan (Radiation): A functional imaging of the dopamine transporter using the radioligand \[123I\]FP-CIT
• F18-AV-45 (Radiation): A brain scan to to measure the extent of amyloid deposition
• FDG-PET (Radiation): a brain scan measuring total and regional cerebral glucose metabolism wtih positron emission tomographs with 2-(18F)
• APOE genotype (Genetic): 10 ml of whole blood will be drawn and shipped to Athena Diagnostics for genetic testing.
• Polysomnogram (Procedure): Overnight sleep study
• Clinical Assessment (Behavioral): Clinical assessments include cognitive, behavioral, and motor evaluations

Primary outcomes

• Mini Mental State Examination (MMSE-1) [Baseline]: Global neuropsychological measure
• Wechsler Adult Intelligence Scale 4th edition (WAIS-4) Vocabulary [Baseline]: Neuropsychological measure of premorbid IQ estimate
• Wechsler Adult Intelligence Scale 4th edition (WAIS-4) Digit Span [Baseline]: Neuropsychological measure of attention
• Wechsler Adult Intelligence Scale 4th edition (WAIS-4) Block Design [Baseline]: Neuropsychological measure of visuospatial perception/ reasoning
• Wechsler Adult Intelligence Scale 4th edition (WAIS-4) Matrix Reasoning [Baseline]: Neuropsychological measure of executive functioning
• Wechsler Adult Intelligence Scale 4th edition (WAIS-4) Reliable Digits (embedded measure) [Baseline]: Neuropsychological measure of effort
• Wechsler Memory Scale 3rd ed. (WAIS-3) Spatial Span [Baseline]: Neuropsychological measure of attention
• Wechsler Memory Scale 3rd ed. (WAIS-3) Logical Memory 1 & 2 [Baseline]: Neuropsychological measure of memory
• Trail Making Test A [Baseline]: Neuropsychological measure of executive functioning/psychomotor processing speed
• Trail Making Test B [Baseline]: Neuropsychological measure of executive functioning
• Boston Naming Test [Baseline]: Neuropsychological measure of language
• Controlled Oral Word Association Test (COWAT)- Animal Naming [Baseline]: Neuropsychological measure of language/verbal fluency
• Judgment of Line Orientation Standardized Test [Baseline]: Neuropsychological measure of visuospatial perception/ reasoning
• Brief Visuospatial Memory Test (BVMT) [Baseline]: Neuropsychological measure of memory
• California Verbal Learning Test (CVLT-2) [Baseline]: Neuropsychological measure of memory
• Wisconsin Card Sorting Task [Baseline]: Neuropsychological measure of executive functioning
• California Verbal Learning Test (CVLT-2) Forced Choice (embedded measure) [Baseline]: Neuropsychological measure of effort
• Self Administered Gerocognitive Examination- A brief cognitive assessment instrument for mild cognitive impairment and early dementia [Baseline]: Global neuropsychological measure
• Apolipoprotein E (APOE) Genotyping of a whole blood sample [Baseline]: 10 ml of whole blood will be drawn for APOE genotyping
• Clinical Dementia Rating Scale (CDR) [Baseline]: Global cognitive and functional measure
• The Activities of Daily Living (ADL) Standardized Scale [Baseline]: Functional measure
• Mayo Fluctuations Scale [Baseline]: Behavioral measure
• Neuropsychiatric Inventory (NPI) [Baseline]: Behavioral measure
• Beck Depression Inventory 2nd ed. [Baseline]: Behavioral measure
• The Modified Somatic Perception Questionnaire [Baseline]: Behavioral measure
• The Epworth Sleepiness Scale [Baseline]: Sleep measure
• Mayo Sleep Questionnaire-Informant [Baseline]: Sleep measure
• Functional Outcomes of Sleep Questionnaire-10 [Baseline]: Sleep measure
• Part III and IV of the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) [Baseline]: Gait, Mobility, and Coordination Measure
• Berg Balance Scale (BBS) [Baseline]: Gait, Mobility, and Coordination Measure
• Florbetapir (F18-AV-45) positron emission tomography (amyloid PET) [Baseline]: Imaging to determine extent of amyloid deposition
• Single-photon emission computed tomography (SPECT) with the radioligand [123I]FP-CIT [Baseline]: Functional imaging of the dopamine transporter
• Positron emission tomography with 2-(18F) fluoro-2-deoxy-d-glucose (FDG-PET) [Baseline]: Imaging to determine total and regional cerebral glucose metabolism
• Brain MRI [Baseline]: Imaging including a resting state functional MRI, diffusion tensor imaging, and anatomic imaging
• Polysomnogram [Baseline]: participants will have an overnight standard clinical polysomnogram with added limb leads assessing for presence of sleep apnea, periodic limb movements, and rapid eye movement (REM) sleep characteristics

Other outcomes

• Lumbar Puncture to obtain cerebrospinal fluid (CSF) that will be stored for future potential evaluation of biomarkers [Baseline]: Optional outcome measure which will be done to obtain samples of CSF
• Post-mortem brain donation to The Ohio State University Neurodegenerative Disease Brain Tissue Repository, for clinicopathological correlations [Post mortem]: Optional outcome measure for patients post-mortem to asses for neuropathologic conditions

Sex: All, ages: 18 Years to any

Inclusion Criteria:

* Subjects must meet the standard clinical criteria of the syndromes of interest
* All subjects must have enough cognitive abilities to complete study procedures, which will be operationally defined as having a Mini Mental State Examination (MMSE) score greater or equal to 10.
* Subjects must be on stable cognitive and psychoactive medication regimen for the preceding four weeks of enrollment.
* Subjects must have a responsible study partner that either lives with them or is in regular contact with them at least 4 out of 7 days per week.
* Subjects must have visual and auditory acuity adequate for testing.

Exclusion Criteria:

* Any other condition (other than the primary diagnosis), which in the opinion of the investigators might contribute to the syndrome of dementia or complicate its assessment.
* active medical disorder that could preclude participation in this protocol
* Women who are pregnant or are breast feeding
* severe renal impairment as defined by glomerular filtration rate (GFR) less than 30 (may have increased radiation exposure with the DaTscan).
* Subjects in whom English is not the 1st language
* Subjects with educational level less than 12 years
* Subjects who have ever participated in an experimental study with an amyloid targeting agent unless it can be documented that the subject received only placebo during the course of the trial.

• Douglas W Scharre, MD, Principal investigator, Ohio State University